Dozens of people remain "trapped" underground following the collapse of a gold mine in northeastern South Africa.

A spokesman for the Association of Mineworkers and Construction Union (AMCU) initially said around 115 of its members were "unaccounted for" after offices at Lily Mine in Barberton, 224 miles east of Johannesburg, "tragically caved-in" at 8.40am local time on Friday.

Mike McChesney, chief executive of the small gold producer Vantage Goldfields, said most workers had been rescued and brought to the surface.

"Mine rescue services are still busy on scene to rescue the remaining miners underground," the ER24 rescue service said.

Trapped miners were brought to the surface through ventilation shafts, the Barberton Times reported.

It said between 60 and 70 people had been rescued and taken to hospital for treatment.

Mike Begg, operations director at the mine, also known as Makonjwaan, told the newspaper the so-called lamp room - the last stop where workers receive lamps and safety packs before being lowered deeper into the ground - at the main entrance to the mine had collapsed.

"We have sent some of our own staff underground to try and come in from behind that area to see whether there are any survivors from that building, who may have been able to crawl out and into one or two of the old tunnels," he told the paper.

He said rescue workers were in touch with those that remain trapped as lists were being checked to find out who was scheduled to work today, and confirmed five miners remained unaccounted for.

Vantage Goldfields is an Australia-based company mining gold at Barberton.

The union said it wanted criminal charges to be brought against the owners and management should investigations reveal that negligence was involved in the collapse.